Roy Hodgson's men secured automatic qualification for the tournament next summer as winners of Group H when they beat Poland 2-0 at Wembley on Tuesday night.
And Liverpool striker Sturridge says the tough qualifying campaign has brought the squad close together and that spirit will help them in South America.
Put to him that the squad looks united, Sturridge said: "It is very fair to say. It is all about working together as a team and going out there to perform.
"The squad has been close the whole time I have been here. It is always good to link up with each other again."
Sturridge, Rooney and Danny Welbeck played in an attacking formation in the last two games, and Sturridge said: "We have time to develop that understanding now and I look forward to that and working with these guys in the future and for years to come.
"We played very well as a team in both games and if we keep doing that, we will be okay.
"I was very relaxed (going into the Poland game). I didn't feel any pressure, it was just another game for me.
"I didn't feel like it was anything more special; if I did I'd put myself under pressure. I took a relaxed approach.
"It is going okay (at Liverpool). I am going to take each day as it comes, work hard in training and thanks to God for everything he has blessed me with.
"I am now focusing on performing for my club and making sure I get on the plane (to Brazil)."